(function (doc, win) {
    var docEl, resizeEvt, recalc
    docEl = doc.documentElement
    resizeEvt = 'orientationchange' in window ? 'orientationchange' : 'resize'
    recalc = function () {
        var clientWidth
        clientWidth = docEl.clientWidth
        if (!clientWidth) return
        docEl.style.fontSize = 20 * (clientWidth / 320) + 'px'
    }
    if (!doc.addEventListener) return
    win.addEventListener(resizeEvt, recalc, false)
    doc.addEventListener('DOMContentLoaded', recalc, false)
})(document, window)
